Frequently asked questions

Have an important question that is not here?

Please drop me an email and explain why you think this question needs to be covered in the FAQ. In the meantime you are likely to find the answer to your question in the Publish or Perish Manual or the Publish or Perish Tutorial.

Top questions

Search questions

Missing papers or references

Duplicate entries

Other results issues

Software installation issues

Support Publish or Perish

The development of the Publish or Perish software is a volunteering effort that has been ongoing since 2006. Download and use of Publish or Perish is and will remain free (gratis), but your support toward the costs of hosting, bandwidth, and software development are appreciated. Your support helps further development of Publish or Perish for new data sources and additional features.

Most asked questions

Author disambiguation (getting only the author you want)

This is a very tricky problem. Even commercial databases like Thomson Reuters Web of Science (ISI) have problems with this, see:

  • Harzing, A.W. (2016) Health warning: Might contain multiple personalities. The problem of homonyms in Thomson Reuters Essential Science Indicators, Scientometrics, vol. 105, no. 3, pp. 2259-2270. Available online...

Please also remember that PoP results are based on Google Scholar and Microsoft Acacemic, which are free services (just like PoP) and not a manually curated bibliometric database with a very high subscription fee, such as Scopus or the Web of Science.

However, there is a lot you can do to get the right author by "smart searching". Have a look at the Publish or Perish tutorial which has lots of tips and tricks. In particular, read the pages on author disambiguation.

Bring back the subject categories (It is Google, not me, who removed them!)

Many longstanding users are asking me to reinstate the subject/discipline categories. Removing them was certainly not my choice; I am even more annoyed than you are as I need to explain this to everyone seeking support. Google Scholar abolished them in 2012; they claim they were not used by most users. For more information on this:

Can you please add/correct [...]? (sorry, no I do not maintain a publication database)

Please remember PoP is an interface to Google Scholar (and, since PoP version 5, Google Scholar Profiles and Microsoft Academic). I do not sit up at night entering your publications in my "Harzing system" as some users seem to think :-).

Google Scholar's and Microsoft Academic's processing is automatic (unlike Scopus and Web of Science which are manually curated databases, with the associated price tag) and hence occasional errors do occur. For more information limitations of Google Scholar, see the Google Scholar pages in the PoP tutorial.

I have no influence on how Google Scholar or Microsoft Academic parse their data, so you will need to contact them for any problems with your publications or citations. For more information, see the Accuracy page of the Publish or Perish manual.

Why do you give me these stupid captchas? (It is Google, not me!)

Again, please remember PoP is an interface to Google Scholar. I have absolutely no interest in blocking your use of Publish or Perish. However, Google Scholar insists on asking you to verify you are a human, not a robot, if you do regular searches. Believe me, I like this even less than you do as I get your angry emails. For more information see: Google Scholar: Captchas.

If you are running PoP under Linux or OSX (Mac) and you cannot see the captcha images, you will need to update your Wine version. Please refer to the linked pages for further details.

Please note: Google Scholar Profile searches are not subject to the same captcha requests; Microsoft Academic does not display these limitations either.

Why is my h-index in PoP different from ... [Google Scholar,Web of Science, Scopus]?

  1. Provided you use exactly the same search syntax in both, your h-index in PoP and GS will identical (see Accuracy: PoP vs GS).
  2. The Web of Science (ISI), Scopus, Google Scholar and Microsoft Academic have different levels of coverage for different disciplines. For a comprehensive comparison, please see: Microsoft Academic: is the Phoenix getting wings?

For detailed information see also:

I'm getting an "Invalid certificate" error when performing a query

This may occur in Publish or Perish version 5.x if you are still using Windows XP. You will typically see a dialog box similar to the following:

Invalid certificate warning

The underlying cause of the error message is a mismatch between the SSL certificate that Publish or Perish expects for its connection to Google Scholar and the actual certificate provided by Google Scholar's server.

It appears that Google sends an SSL certificate for www.google.com instead of scholar.google.com or *.google.com for requests that originate from older versions of Internet Explorer (such as IE8 that Publish or Perish uses on Windows XP, because no later versions than Internet Explorer 8 are available for Windows XP).

A more sinister potential cause is that you are using a web proxy (perhaps your organisation's) and that its SSL certificates are invalid or even compromised, or that you are using an anti-virus tool or similar security program that actively intercepts HTTPS connections and offers its own SSL certificates.

There are several (partial) solutions to this issue, depending on the exact cause. You will have to try them each until you find one that works.

Before you start, make sure that you are using Publish or Perish 5.27 or later. We have added some automatic mitigations for the certificate problems in this version of Publish or Perish.

  1. Simply click "Yes" when asked if you want to proceed. This doesn't solve anything, but it might get you through. It might be necessary to retry your query after clicking Yes for the first time.
    --or--
  2. Make sure that you are NOT using a proxy. Proxies are often badly configured, particularly when you try to perform HTTPS (secure) web connections. You can find the applicable proxy settings, if any, by choosing Tools > Internet Options from PoP's main menu, then going to the Connections tab, clicking on the LAN settings button, and making sure that no proxy is configured.
    --or--
  3. Change the Google Scholar URL (if you are trying to perform a Google Scholar lookup, and not Microsoft Academic) to use plain HTTP (insecure) instead of HTTPS (secure): choose Tools > Preferences on the PoP main menu, go to the Google Scholar tab, and edit the Query URL field so it starts with http:// instead of https:// This won't work for Microsoft Academic --which always uses HTTPS-- and may not work much longer for Google Scholar, because Google is also transitioning to HTTPS-only.
    --or--
  4. Upgrade your system to at least Windows 7 and at least Internet Explorer 11, and make sure that all "recommended" Windows Update updates have been applied.

Search questions

Why have Google Scholar queries become so much slower?

To avoid exceeding the maximum acceptable Google Scholar request rate.

In February 2013 Google Scholar reduced the maximum number of results per page from 100 to 20. This means that Publish or Perish now has to retrieve up to 5 times as many result pages per query in order to show the full results.

  • More page requests mean that Publish or Perish hits the maximum number of requests that Google Scholar allows per hour sooner.
  • If the number of page requests exceeds the maximum that Google Scholar allows, your IP address will be temporarily blocked by Google Scholar. This block can last for up to 24 hours.
  • To avoid hitting the maximum allowable request limit, Publish or Perish now uses an adaptive request rate limiter. This limits the number of requests that are sent to Google Scholar within a given period, both short-term (during the last 60 seconds) and medium term (during the last hour).
  • To achieve the required reduction in requests, Publish or Perish delays subsequent requests for a variable amount of time (up to 1 minute). The higher the recent request rate, the longer the delays.

The net result is that queries will take longer than before. The alternative is being blocked by Google Scholar for up to 24 hours. We consider the relatively short delays during queries as the lesser evil, hence the adaptive rate limiter. If you perform queries with few results or only occasionally, then the request rate limiter will have little or no effect on the query time. In this case, the required delays are short or non-existent, and Publish or Perish will retrieve result pages as fast as it did in the past.

However, if you perform queries that yield many results (several hundred or more) or issue a number of queries in short succession, then the request rate limiter will insert progressively longer delays to keep the overall request rate within acceptable limits. If you want to avoid this, then the best remedy is to spread your queries over the day.

To use the adaptive request rate limiter, make sure that:

Publish or Perish only searches for English names?

Not so; you can search for any name (or other words) regardless of the language.

Publish or Perish submits your query properly encoded to Google Scholar, so as long as Google Scholar has matching data, the information will be found. However, it can be that Google Scholar's coverage of non-English source material is less complete than that of English.

How do I search for names with accents?

If you are looking for an author whose name contains accented letters, then it might help if you include several variations of the name, both with and without accents, and also with the accented letters missing. The reason for the latter is that some sources used by Google Scholar cannot handle accented letters and simply omit them.

For example, to search for someone with the surname Veríssimo (note the accent on the first 'i'), use the following names in the Author field:

Veríssimo OR Verissimo OR Verssimo 

I have published under several names. How do I find all my papers?

By using an OR query in the Author name field and specifying all names under which you published. For example, if you changed you name when you married, then use a query that includes both your maiden name and your married name.

How do I exclude self-citations from the results?

You cannot do so directly.

Publish or Perish uses Google Scholar data or Microsoft Academic data and identifying self-citations requires numerous follow-up queries, potentially exceeding the acceptable number of Google Scholar and Microsoft Academic queries. For that reason, Publish or Perish restricts your queries to first-level queries only. If you want to exclude self-citations, you must identify them yourself and then exclude them from the Results list by clearing their check boxes.

Can I use Boolean expressions to restrict an author search?

Unfortunately, Google Scholar and Microsoft Academic don't seem to support complicated Boolean queries and do not have any systematic information on what they do support. From experience, you can conduct an "OR" query, but it does not seem to be possible to combine or exclude authors ("jj smith" AND NOT "j smith "). You might wish to run some experiments in the general citation search tab to see whether that delivers better results.

The following seem to work with the Author's name field:

  • To perform an "and" search, enter multiple author names separated by AND
  • To perform an "or" search, enter multiple author names separated by OR

How do I search for all publications by authors affiliated with <my university name>?

You cannot do so directly.

Google Scholar does not have a bibliographic field listing affiliation in the same way as ISI does. Hence a search like the one you describe will not always give reliable results. You can try to search with your university name in the General Search All of the words field (for details see: General Search: Institutions), but this will match the name anywhere in the documents (not only as author affiliation) and for some universities is not comprehensive. Currently, we therefore cannot recommend this type of analyses with Google Scholar beyond very general curiosity driven experiments.

Can I use Publish or Perish to identify the main publications in a certain area?

Yes, up to a point. Search for relevant keywords in either the All of the words or The phrase field (see helpfile for description of these fields). For Google Scholar you might want to tick Title words only if you think that the most relevant works will have the keywords in their title; Microsoft Academic by default only searches in the title and abstract.

The most cited results are (probably) the main publications.

Can I use Publish or Perish to identify the main authors in a certain area?

Yes, up to a point. You can find the main authors (or at least the most cited ones) in both a subject area and in a specific journal.

In a subject area: Search for relevant keywords in either the All of the words or The phrase field (see helpfile for description of these fields). You might want to tick Title words only if you think that the most relevant works will have the keywords in their title; Microsoft Academic by default only searches in the title and abstract.

In a specific journal: Search for the relevant journal in the Journal title field. You may want to restrict your search to a certain period by using the Year of publication fields.

The most cited results belong to (probably) the main authors in the field or journal. You can also sort the results list on the Authors column; this groups papers by the same author together and may tell you at a glance who the most active authors are in a given area or journal.

Missing papers or references

Publish or Perish doesn't find any of my papers!

Assuming that you really have published scholarly papers, there may be several reasons why Publish or Perish doesn't return any results for your name.

  • You spelt your name incorrectly. Correct any typos and try again.
  • You entered your given names in full instead of as initials. This may find some papers, but many publishers only list the author's initials and a full name search misses those papers. To be on the safe side, try using both full names and initials in a single query, like this (the "quotes" are highly recommended): "A Harzing" OR "Anne-Wil Harzing"
  • Your papers are not available online, neither through your publishers nor through your own web pages. If that is the case, then Google Scholar and Microsoft Academic do not know about your papers.
  • You published in a language other than English. Google Scholar's and Microsoft Academic's coverage are improving, but non-English publications still are underrepresented in the results.

Here are more search tips and an explanation of Google Scholar limitations.

My paper/book does not appear in Publish or Perish. Can you correct this?

Sorry, no. We do not personally maintain a database of academic publications.

Publish or Perish uses Google Scholar and Microsoft Academic data to calculate its citation metrics. Their processing is automatic (unlike ISI's or Scopus' that involves manual handling and checking, with the associated price tag) and hence occasional errors or omissions do occur.

This may be due to:

  • Papers that are not (yet) available online. This includes many older papers.
  • The nature of the publication: some books and other non-journal publications might not be accessible to Google Scholar or Microsoft Academic.
  • Publishing in journals to which Google Scholar or Microsoft Academic has no access because of the journals publishers' policy.

For more information limitations of Google Scholar, see the Google Scholar pages in the PoP tutorial.

The number of citations for my paper is too low. Can you correct this?

Sorry, no. We do not personally maintain a database of academic publications.

As indicated elsewhere on the this website, Publish or Perish uses Google Scholar and Microsoft Academic data to calculate its citation metrics. Their processing is automatic (unlike ISI's or Scopus' that involves manual handling and checking, with the associated price tag) and hence occasional errors or omissions do occur.

This may be due to:

  • Incorrect or sloppy referencing of your paper by others. Try to find the referencing works to see if this is the case.
  • References in older journals or in journals that are not available online. Google Scholar only uses online information; if your paper or the references to it are not online, they will be omitted.
  • References in journals to which Google Scholar or Microsoft Academic has no access because of the journals publishers' policy.

For more information limitations of Google Scholar, see the Google Scholar pages in the PoP tutorial.

Publish or Perish does not find all my publications, but Google Scholar does. Why?

Publish or Perish uses the Google Scholar Advanced Search options. This is not the same as the standard Google Scholar search box. The search results might differ for one or more of the following reasons:

  • A Google Scholar general search returns papers in which the search terms that you entered appear anywhere - as author, title, or even in the contents. In contrast, a Publish or Perish search is more specific and will only return papers that match in the fields that you specified: author names only in the author field, title words only in the title, etc.
  • Perhaps Google Scholar did not classify your name correctly as an "author", but somewhere else (for example as part of the title - this is usually due to sloppy references to your article). A Google Scholar general search will still include the paper, but the more specific search that Publish or Perish uses will not if it does not find your name in the "Author" field.

For more details on this, please see Accuracy of the results.

Publish or Perish does not find all my publications, but Web of Science or Scopus does. Why?

Perhaps your academic field is not fully covered by Google Scholar and Microsoft Academic.

Publish or Perish uses Google Scholar or Microsoft Academic data to calculate its citation metrics. Although in general coverage of both these sources is more comprehensive than Scopus or the Web of Science, this might not be true for every individual academic. If you prefer to use Web of Science of Scopus data, refer to the linked pages for information on how to import data from these sources.

I am a journal editor. How do I get Publish or Perish to list my journal?

We do not personally maintain a database of academic publications.

Publish or Perish uses Google Scholar and Microsoft Academic data to calculate its citation metrics. You will therefore need to contact them to include your journal. Once they do, Publish or Perish will use the same data.

Duplicate entries

My paper appears as several different entries in Publish or Perish. Can't you combine these?

Publish or Perish uses Google Scholar and Microsoft Academic data and these data occasionally split what you know is a single paper into multiple entries. This is usually due to incorrect or sloppy referencing of your paper by others, which causes Google Scholar to believe that the referenced works are different. As of Publish or Perish release 3.0.3780 it is possible to merge duplicate results manually in the results list.

My paper is duplicated under different languages of the same journal. Can't you combine these?

Publish or Perish uses Google Scholar and Microsoft Academic data and these data sources will typically consider different language editions of what you know as the same journal as separate journals. For example, English and French versions of a Canadian journal (or merely of different versions of the journal title) will typically be considered to be different. As of Publish or Perish release 3.0.3780 it is possible to merge duplicate results manually in the results list.

Other results issues

How do I improve the accuracy with which Google Scholar lists my papers?

In general, this is rather difficult, because a lot depends on the accuracy with which your papers are referenced by others.

However, if you have separate web pages for each of your papers, then Google Scholar advises that you can add several meta tags to your pages to help Google's crawler to list your paper. In particular, they recommend using the following tags (replace the content="..." bits with your own information):

<meta name="citation_journal_title" content="Journal Name">
<meta name="citation_authors" content="Last Name1, First Name1; Last Name2, First Name2">
<meta name="citation_title" content="Article Title">
<meta name="citation_date" content="01/01/2007">
<meta name="citation_volume" content="10">
<meta name="citation_issue" content="1">
<meta name="citation_firstpage" content="1">
<meta name="citation_lastpage" content="15">
<meta name="citation_doi" content="10.1074/jbc.M309524200">
<meta name="citation_pdf_url" content="http://www.publishername.org/10/1/1.pdf">
<meta name="citation_abstract_html_url" content="http://www.publishername.org/cgi/content/abstract/10/1/1">
<meta name="citation_fulltext_html_url" content="http://www.publishername.org/cgi/content/full/10/1/1">
<meta name="dc.Contributor" content="Last Name1, First Name1">
<meta name="dc.Contributor" content="Last Name2, First Name2">
<meta name="dc.Title" content="Article Title">
<meta name="dc.Date" content="01/01/2007">
<meta name="citation_publisher" content="Publisher Name">

If you don't know what meta tags are, then this information is not for you.

What is this error 13?

This means that the Google Scholar response to your query contained no recognizable data. Possible causes include:

  • The Google Scholar output format has changed.
  • Your Internet connection does not work.

While we try to adapt as quickly as possible to changes in the Google Scholar output format, there may be a delay of a few days after Google Scholar introduces a new format.

Furthermore, even after we release a new version of the software, you must update your own copy of Publish or Perish to receive the benefit of the new software version. You can do so through the Publish or Perish web page, or by using the Help > Check for Updates command from the Publish or Perish main menu.

After updating the Publish or Perish software, retry the query using the Lookup Direct button (instead of Lookup). This retrieves fresh query data from Google Scholar, which might resolve the problem.

If nothing else helps, then please lodge an error report to Publish or Perish technical support as follows:

  1. Repeat the query that failed.
  2. Choose the Tools > Report Error command from the main menu.

This generates an error report (a plain text file) called PoPError.txt that you should attach to your email to the Publish and Perish support address. We need the information in the error report for an accurate diagnosis.

What is this error 1169?

This means that the Google Scholar response to your query contained no entries. Possible causes include:

  • A query that did not match any papers. Try changing the query parameters.
  • Your Internet connection does not work.

What is this error 8228?

This means that the Google Scholar response to your query contained a refusal to accept further requests from your IP address. This is usually caused by an excessive number of prior queries. Google Scholar will normally lift the block after 24 hours.

In most cases, you can prevent this type of block by using Publish or Perish's adaptive request rate limiter. This limiter is enabled by default as of Publish or Perish release 4.0.12.

If you are unlucky, it could be that your computer is located behind a web proxy that forwards your queries and those of your colleagues to Google Scholar. In that case, all those queries appear to come from a single system as far as Google Scholar is concerned, which may cause it to block further queries from any of you. Contact your local system administrator if you suspect that this might be the case.

Tip: As of Publish or Perish 4.0.15, you can enable Google CAPTCHA support in Publish or Perish by checking the Respond to verification requests option. When enabled, Publish or Perish will respond to Google's request for human identification and present the CAPTCHA image from Google. You can then type in the words shown in the image and submit them to Google. If you solved the CAPTCHA correctly, then Google will allow further access from your Publish or Perish session.

Can Publish or Perish automatically identify authors in the list of results?

No; this is too difficult with the current results from Google Scholar. Here is what the Publish or Perish developer had to say about this when he investigated the issue in March 2009:

Hi Anne-Wil,

I have looked into the weighted author contribution issues that you
raised, and here are my findings.

(a) The actual calculations are simple enough and not a limiting
factor.

(b) The trouble lies with reliably identifying and tracking individual
authors in a set of results.

Let me clarify point (b). In a typical set of Publish or Perish search
results, the Authors field of each results item contains a semi-formatted
list of author names.

It is possible, up to a point, to split each author list into its
separate author names. We already do so for the purpose of the
Individual h-index, and also to provide an overview of papers with 1,
2, 3, etc. authors. For the Individual h-index this is sufficient,
because each author receives the same weight (namely, 1/n if 'n' is
the number of authors for that paper).

However, reliably recognizing and tracking a given author, as would be
required for any scheme that assigns unequal weights to authors based
on their position in the authors list, is a different matter.

The Google Scholar data contains a lot of noise (usually through no
fault of Google, but simply the result of sloppy or inconsistent
referencing by humans) that makes this harder than it appears.

To give just one example: an author search for "a harzing" [sic]
results at the moment [March 2009] in 158 papers, most of which appear
to be (co-)authored by you. Looking at the results, your name appears as:

  A Harzing
  AK Harzing
  AW Harzing
  AWK Harzing
  AWIL Harzing

...but in some of the results it doesn't appear at all. Now you and I
may know that all these variations refer to the same person (you), but
this cannot be universally assumed:

- For an author search, the search phrase "a harzing" might give a
clue, but only if you are prepared to follow English naming
conventions of one or more initials followed by a surname. For other
cultural conventions, this might not be appropriate.

- What if the author search phrase used several author names, like:

    "a harzing" OR "c kulik"?

- For non-author searches, you don't even have this starting point.

- For any searches, you might want to extract a list of all author
names from the results, but then the matching process across the
results set is even iffier -- perhaps not for semi-unique names such
as Harzing, but certainly for the Smiths and Browns of this world.

- And then there are completely garbled results, like this one from
the same sample:

  Authors: AW Harzing, R Wal
  Title: van der (2008). A Google Scholar h-index for journals...

This refers to the article you co-wrote with "R van der Wal", but no
algorithm would be able to find this person in the Authors field.

Therefore, to get this to work, we would have to implement some sort
of user interface that allows the user to indicate which authors
should be combined. This in itself is not rocket science, but it will
take more development work to make it usable to the average user than
we have available at the moment.

Why does Publish or Perish always count years until the current year, and not the indicated period?

Situation: You have just done a search (any search) with specific start and end years, for example from 2000 to 2005. However, the results do not show "6 years active" as you expected, but "10 years active" (if the search is done in 2009). What's going on?

Answer: The search period (2000 to 2005 in the example) restricts the original publications. It does not restrict the citations.

Regardless of the start and end years in your query, the results will always show the citations until the present day, give or take a few weeks. And because Publish or Perish shows citation statistics, we must count all years from the start year until the present day.

Before you ask: No, Publish or Perish does not have control over this aspect of the results; it's Google Scholar that provides these data.

Software installation issues

Updating Publish or Perish fails with error code 740

This occurs when you try to update the Publish or Perish software on Windows XP and later (including Vista and 7). The full error message is:

Error 740 while updating the software.
The required operation requires elevation.

This is caused by an old version of the update software; it is not related to the Publish or Perish software itself. To resolve it, do the following.

  1. Close any running instances of the Publish or Perish software.
  2. Download the latest version of the software from the Publish or Perish page. This will result in a file called PoPSetup.exe on your computer.
  3. Run the PoPSetup.exe program that you just downloaded. This will update the Publish or Perish software on your computer to the latest version.

This procedure needs to be performed only once; later versions of the Publish or Perish updater no longer cause the error message.

Installation under Wine on Linux fails with "Call to unimplemented function"

This is a problem in Wine.

The DLL (sxs.dll) and function (CreateAssemblyCache, or a related function) in question are not available on all Windows platforms, so our installer very carefully:

  1. Checks for the presence of sxs.dll, then
  2. Checks for the availability of CreateAssemblyCache, and only then
  3. Calls that function.

What Wine does wrong is to provide the DLL and the function, but then bomb out when the function is called. What they should do instead is either not provide the function at all, or just return an error code when it's called.

Update: This problem was resolved in Wine release 1.1.20 when sxs.CreateAssemblyCache() was modified to return an error code (E_NOTIMPL) rather than causing a fatal error (fix courtesy of Kai Blin). If you experience this issue, then update your Wine installation to release 1.1.20 or later; this should resolve the problem. You can then use the normal Windows installer as documented on the Publish or Perish on GNU/Linux page.

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